1. Field of the Invention
The present invention relates to a submersible, water cooled, electric outboard motor of modular construction which allows motor power ratings and propeller drive gear ratios to be readily changed depending on the particular application. In addition the present invention allows a shroud or nozzle to be provided around the propeller at the users option.
2. Description of the Prior Art
Shrouded propellers are well known in the prior art, as are electric motors for use in aquatic propulsion systems.
U.S. Pat. No. 4,789,302, issued to Gruzling, is directed to the hydrodynamic design of propeller shrouds. U.S. Pat. No. 5,145,428, issued to Harrison, and French patent 1,348,243, show shrouds around the propellers of gasoline powered outboard motors. None of these patents teach or suggest the modular and quick disassembly features of the present invention.
U.S. Pat. No. 5,101,128, issued to Veronesi et al., shows an electric marine propulsion system having a shrouded propeller. The propulsion system of U.S. Pat. No. 5,101,128 is not directed to maintaining a watertight environment around a motor-gearbox assembly, in contrast to the present invention, because the motor windings of the propulsion system of U.S. Pat. No. 5,101,128 are designed to be immersed in water.
U.S. Pat. No. 4,864,959, issued to Takamizawa et al., U.S. Pat. No. 3,957,007, issued to Thomas, and U.S. Pat. No. 4,996,938, issued to Cameron et al., show devices for propelling a SCUBA diver through the water. None of these patents show the unique construction of the present invention which uses an O-ring seal and an internally threaded retaining ring to maintain a watertight environment around an electric motor-gearbox assembly.
U.S. Pat. No. 4,993,977, issued to Rodler, Jr., shows an electric propulsion system having a gearbox and a shrouded propeller. However in U.S. Pat. No. 4,993,977 the propeller hub acts as the gearbox housing. Therefore U.S. Pat. No. 4,993,977 must use a complex ball bearing based arrangement for retaining the propeller hub about the gearbox. U.S. Pat. No. 4,993,977 does not teach or suggest the unique construction of the present invention which uses an O-ring seal and an internally threaded retaining ring to maintain a watertight environment around an electric motor-gearbox assembly.
U.S. Pat. No. 5,102,359, issued to Hinds, shows a conventional electric trolling motor with two flanking plates installed on either side of the propeller to; enhance the steering ability of the electric trolling motor. U.S. Pat. No. 3,599,168, issued to Long, U.S. Pat. No. 3,593,050, issued to Ware, and U.S. Pat. No. 2,116,146, issued to Gondek, show conventional electric trolling motors. None of these patents show the unique construction of the present invention which uses an O-ring seal and an internally threaded retaining ring to hold the aquatic propulsion assembly together.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.